B. Schneider et Kk. Shung, QUANTITATIVE-ANALYSIS OF PULSED ULTRASONIC BEAM PATTERNS USING A SCHLIEREN SYSTEM, IEEE transactions on ultrasonics, ferroelectrics, and frequency control, 43(6), 1996, pp. 1181-1186
The acoustic output from pulsed ultrasonic transducers has traditional
ly been analyzed with a hydrophone. Recently, a new faster technique h
as been developed using the principles of optical diffraction, This sc
hlieren method allows the direct two-dimensional visualization of the
ultrasonic beam as a pulse train, In order to obtain quantitative info
rmation in the form of temporal-average acoustic intensity, however, t
omographic reconstruction has to be performed. In this study, tomograp
hic reconstruction was achieved by acquiring 250 images over a 180 deg
rees angle, Automation of the measurement was obtained by using a fram
e grabber, a stepper motor, and digital delays all controlled by an IB
M-compatible computer, Comparisons of the schlieren results to those o
btained by a hydrophone are made in terms of both the -3 dB beamwidths
and axial profiles, The results demonstrate that the schlieren method
may be a more time efficient alternative for the characterization of
ultrasonic transducers.